In recent years, heat assisted magnetic recording is considered promising as one of the technique to improve areal density of hard disk drives drastically.
In order to improve areal density, it is necessary to make the bit size of recording lower. However, data missing is caused by heat fluctuation when making the bit size of the recording lower excessively. To prevent from such data missing, we should use high coercivity medium. However, ordinal magnetic heads cannot write data to the high coercivity medium. Hence, heat assisted magnetic recording is proposed: the heat assisted magnetic recording is the technique that writing is done after a spot, the size of which is about several ten nano meters×several ten nano meters, is heated more than to 200 degrees Celsius only when using the high coercivity medium. As the means for heating this spot, the utilization of near-filed light is examined. That is, the heat assisted magnetic recording head considered the utilization of near-filed light comprises a near-field transducer and waveguide in addition to write poles and a read element, and in the head. And laser beam passes through the waveguide, is conducted to the near-field transducer in the neighborhood of the writepoles, and is converted into near-field light by the near-field transducer.
As to a background art, for example, the below Patent Document 1 is already known. That is, this Patent Document 1 discloses as follows:    “The slider comprises a slider substrate, an electromagnetic transducer element, a near-field transducer, a waveguide receiving light from the reverse face of a medium opposite face, and conducting light to the medium opposite face, an electrode for an element electrically connected to the electromagnetic transducer element; the light source unit (LD unit: Laser Diode unit) comprises a light source supporting substrate (submount), a light source (LD: Laser Diode), a lead extending from the slider side to the opposite side of the slider, whose both ends are exposed on the surface of the light source unit; the electrode for the element of the slider is exposed on the reverse face of a medium opposite face without being covered by the light source unit; and the end of the lead at the side of the light source and the electrode for the element of the slider are soldered each other (Refer to Abstract).